# Rough engine performance

**URL:** <https://community.cartalk.com/t/rough-engine-performance/86884>\
**Category:** Maintenance/Repairs\
**Created:** [August 30, 2014, 2:57am UTC](https://community.cartalk.com/t/rough-engine-performance/86884 "2014-08-30T02:57:30Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![FRANKIE\_3](https://avatars.discourse-cdn.com/v4/letter/f/73ab20/32.png) [@FRANKIE\_3](https://community.cartalk.com/u/FRANKIE_3)\
**Post date:** [August 30, 2014, 2:57am UTC](https://community.cartalk.com/t/rough-engine-performance/86884/1 "2014-08-30T02:57:30Z")

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On my 94 Honda Del Sol. When I start up and the engine is cold, it runs fine. Soon, after it warms up, low rpm acceleration is rough until it hits about 2500 rpm. then it gets smooth. If I accelerate slowly during this period, it can be ok. If i open it up at higher rpm., it runs great.

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [August 30, 2014, 5:06am UTC](https://community.cartalk.com/t/rough-engine-performance/86884/2 "2014-08-30T05:06:11Z")

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I would be looking at a thermostat that’s stuck open, or a coolant temp sensor for the computer sending the wrong signal.

Tester

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**Author:** ![knfenimore](https://avatars.discourse-cdn.com/v4/letter/k/9fc348/32.png) [@knfenimore](https://community.cartalk.com/u/knfenimore)\
**Post date:** [August 30, 2014, 5:15am UTC](https://community.cartalk.com/t/rough-engine-performance/86884/3 "2014-08-30T05:15:18Z")

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Also, are the plugs, cap, rotor and wires old?

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**Author:** ![FRANKIE\_3](https://avatars.discourse-cdn.com/v4/letter/f/73ab20/32.png) [@FRANKIE\_3](https://community.cartalk.com/u/FRANKIE_3)\
**Post date:** [August 30, 2014, 9:33pm UTC](https://community.cartalk.com/t/rough-engine-performance/86884/4 "2014-08-30T21:33:01Z")

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While I can’t rule out the rotor, cap, and wires, it just doesn’t seem likely. My reasoning for this is that the car operates normally when cold. The rpm only breaks up at the lower end of the rpm range. At higher rpm’s, I can really wind out the engine without it breaking up. Also, if I am very careful in EASING the gas petal during acceleration, there is no break-up.

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**Author:** ![FRANKIE\_3](https://avatars.discourse-cdn.com/v4/letter/f/73ab20/32.png) [@FRANKIE\_3](https://community.cartalk.com/u/FRANKIE_3)\
**Post date:** [August 30, 2014, 9:34pm UTC](https://community.cartalk.com/t/rough-engine-performance/86884/5 "2014-08-30T21:34:12Z")

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Could it be dirty injectors?